1. Field of the Invention
The present invention relates to an imaging apparatus having at least one bending optical element, and in particular relates to such a type of imaging apparatus which is small in size and equipped with a mechanism for adjusting the inclination of an image sensor.
2. Description of the Related Art
In recent years, mobile electronic devices which are designed mainly for taking still/moving photographic images, such as digital cameras (still-video cameras) and digital camcorders (video cameras), and other mobile electronic devices which are designed to be capable of taking such photographic images as a subsidiary function, such as mobile phones equipped with a camera and smart devices (e.g., smart phones and tablet computers), etc., equipped with a camera, have become widespread, and there has been a demand to miniaturize the imaging unit incorporated in these types of mobile electronic devices. In order to miniaturize an imaging unit, an imaging optical system which is configured from a bending optical system that reflects (bends) an object light bundle using a reflection surface of a reflecting element (bending optical element) such as a prism or a mirror is known in the art. An imaging optical system having at least one bending optical element (hereinafter also referred to as the “bending imaging apparatus”) is advantageous in achieving a reduction in thickness of the imaging unit in the travelling direction of the incident light emanating from an object to be photographed (Japanese Unexamined Patent Publication Nos. 2006-267391, 2010-243763 and 2013-105049).
In such a bending imaging apparatus, an image sensor is arranged on the post-bending optical axis of a bending optical element. The image sensor is usually fixed to an image sensor board provided as a separate member from the image sensor, and the image sensor board is fixed to a housing which supports an imaging optical system (a lens group(s) and a prism(s)). Although a mechanism for adjusting the inclination of an image sensor relative to a plane orthogonal to an optical axis is known in the art, e.g., Japanese Unexamined Patent Publication No. 2006-293187, it is difficult to apply this mechanism to a bending imaging apparatus; if this mechanism is applied to a bending imaging apparatus, the bending imaging apparatus increases in size.